Multiple level lighting systems allow a user to set the level of light the user desires to receive from the lamp or lamps within the lighting system. For example, a two level lighting systems allows the user to select between two different levels of light: full on, such that the lamp or lamps in the lighting system is/are at their maximum output setting, and half on, such that the lamp or lamps in the lighting system is/are at half of their maximum output setting. As a result, multiple level lighting systems are typically used in overhead lighting applications, to give the user a choice between levels of light.
A typical implementation of a two level lighting system includes two power switches and two ballasts. Each power switch in the lighting system controls only one of the ballasts in the lighting system. Turning on both of the switches at the same time powers both ballasts, thus producing full light output from the lighting system. Turning on only one of the switches applies power to only one of the ballasts in the lighting system and thus results in a reduced light level and a corresponding reduction in power consumed.